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Volume 5 Issue 1, January 2019

Volume 5 Issue 1

Pine pollen’s polymer protection

Land plants synthesize the chemically inert polymer sporopollenin at the outer wall of spores and pollen to protect the vulnerable gametes. Its structure is polyvinyl alcohol and coumaroylated aliphatic units, crosslinked through a distinctive dioxane moiety.

See Li, F-S.

Image: Jing-Ke Weng, based on an image by the Dartmouth College EM facility. Cover Design: L. Heslop.


  • Editorial |

    We live in uncertain times, but the changing of the year provides a time not only to look back on the year that has passed, but also to look forward to what might happen in the year to come.

Research Highlights

News & Views

  • News & Views |

    Magnoliid genomes provide novel insight into early angiosperm evolution, showing how whole-genome duplication and proliferation of transposable elements have shaped these genomes. Now, two papers giving differing views of early angiosperm phylogeny, raise questions about the relationships among eudicots, monocots and magnoliids.

    • Douglas E. Soltis
    • Pamela S. Soltis
  • News & Views |

    Sporopollenin, which encapsulates gametes in spore and pollen grains, is probably the most chemically inert biopolymer. This inertness is essential for gamete protection, but also hinders the elucidation of sporopollenin molecular structure. Now, the macromolecular network forming sporopollenin is described in unprecedented detail.

    • Paula Guzmán-Delgado
    • Maciej A. Zwieniecki
  • News & Views |

    The vacuole is a plant’s major phosphate (Pi) pool. Cellular Pi homeostasis highly depends on shuttling Pi between vacuoles and the cytosol. Glycerol 3-phosphate transporter types have now been identified as tonoplast-localized vacuolar Pi efflux transporters, integrating vacuolar Pi transport systems in plants.

    • Mingda Luan
    • Wenzhi Lan


  • Perspective |

    A Perspective summarizes advances in the research of plant diversity, and discusses how big data resources and new technologies, such as analytical and integrating tools, are revolutionizing our views of plant diversification and guiding conservation.

    • Julie M. Allen
    • Ryan A. Folk
    • Robert P. Guralnick


  • Brief Communication |

    The engineered Streptococcus pyogenes Cas9 variant SpCas9-NGv1, known to recognize relaxed NG protospacer adjacent motifs (PAMs) in human cells, can also mediate targeted mutagenesis with NG PAMs in rice and Arabidopsis. When fused with cytidine deaminase, it mediates C-to-T substitutions.

    • Masaki Endo
    • Masafumi Mikami
    • Seiichi Toki
  • Letter |

    Photosynthetic organisms minimize potential harm from excess light by protection mechanisms collectively referred to as non-photochemical quenching. Two proteins involved in quenching, DAMAGED DNA-BINDING 1 and DE-ETIOLATED 1, are part of a complex containing CULLIN 4.

    • Yusuke Aihara
    • Konomi Fujimura-Kamada
    • Jun Minagawa
  • Letter |

    A distinct feature of pollen gains is their resistant outer wall, called the exine, which is mainly composed of sporopollenin, the toughest biopolymer known to date despite an unknown detailed structure. Now, a structural model of pine sporopollenin is revealed by the application of new degradation chemistry and solid-state NMR spectroscopy.

    • Fu-Shuang Li
    • Pyae Phyo
    • Jing-Ke Weng
  • Article |

    Rubber tree plantations have been displacing tropical forests in Southeast Asia, linked to global rubber prices. Forest-to-plantation conversion in Cambodia is correlated with shifts in rubber prices, with a time lag of under a year, showing the link between global commodity markets and deforestation in developing nations.

    • Kenneth Grogan
    • Dirk Pflugmacher
    • Rasmus Fensholt
  • Article |

    Phosphorus is one of the essential nutrients for all living organisms. Plants and fungi store phosphate in their vacuoles. Multiple plant influx transporters have been reported to import phosphate to the vacuoles. Now, two new phosphate efflux transporters are shown to be important for phosphate export from the vacuole in rice and probably other land plants.

    • Lei Xu
    • Hongyu Zhao
    • Keke Yi
  • Article |

    This study characterized the unique protein subunit composition and structure of Arabidopsis mitochondrial ribosomes using biochemical assays and cryo-electron microscopy. Ten subunits are pentatricopeptide (PPR) proteins, among which rPPR1 functions as a translation factor.

    • Florent Waltz
    • Tan-Trung Nguyen
    • Philippe Giegé

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